Calculating machine



May 17, 1949. A. G. THoMAs l2,470,535

CALCULATING MACHINE Filed sept. 3, 194e 9 Sheets-Sheet 1 May 17, 1949. A. G..THoMAs 2,470,535

GALGU'LATING MACHINE Filed sept. s, 1946 9 Sheets-sheet 2 'FHL-mz May 17, 1949- A. G. THOMAS 2,470,535

CALCULATING MACHINE Filed sept. 3, 194e 3A sheets-sheet 5 M INVNTOR.

May 17, 1949. A. G. THOMAS CALCULATING MACHINE 9 Sheets-Sheet 4 Filed Sept. 5, 1946 IN V EN TOR.

May 17, 1949. A. G, THOMAS 2,470,535

CALCULATING MACHINE Filed Sept. 5, 1946 9 Sheets-Sheet 5 g f\ E T 9 man TIES-.IZJ

MZ Mig May 17, 1949. A. G. THOMAS GALCULATING MACHINE 9 Sheets-Sheet 6 Filed Sept. 3, 1946 May 17, 1949.

Filed Sept. 5, 1946 A. G. THOMAS CALCULATING MACHINE 9 She'ets-Sheet 7 May 17, 1949. v A. G. THOMAS 2,470,535

CALGULA'IING MACHINE Filed Sept. 3, 1946 A 9 Sheets-Sheet 8 2| I'NVENTOQ.

May 17, 1949. A. G. THOMAS 2,470,535

CALCULATING- MACHINE Filed Sept. 3, 1 946 9 Sheets-Sheet 9 m mme. 24

Patented May l?, 1949 UNITED STATES PATENT OFFICE CALCULATING MACHINE Albert G. Thomas, Lynchburg, Va.

Application September 3, 1946, Serial No. 694,627

16 Claims. 1

This invention relates to calculating machines.

It is an object of the invention to provide a machine of great simplicity and speed of operation, eliminating the repeated turning of handles and depressing of keys that has hitherto been necessary in many types of calculators.

Another object is to provide a calculating machine which requires, for multiplication for instance, the pressing of the desired keys representing the multiplier and multiplicand only one time in order to obtain the desired result. When these keys have been depressed, it is then necessary to pull the clearing lever only one time to clear the machine in preparation for another calculation.

A further object of the invention is to provide a machine which can be used not only as an adding machine, but also as a multiplying machine.

Another object is toy provide an electrically operated calculator utilizing a step motor construction.

Other objects and advantages of the invention will appear from the following description taken in connection with the accompanying drawings, which illustrate by way of example a preferred embodiment of the invention, but which are not to be taken as a denition of the limits thereof, reference being had to the appended claims for that purpose.

1n the drawings:

Fig. 1 is a top plan view of the calculating mechanism of the present invention.

Fig. 2 is an end elevation thereof of an enlarged scale, viewed from the right of Fig. 1, and showing in some detail the multiplier keys and associated mechanism.

Fig. 3 is a side elevation of the multiplicand keys and supporting sector.

Fig. 4 is a sectional view of the sector of Fig. 3.

Fig. 5 is a fragmentary edge view or detail of the release mechanism for the multiplicand keys.

Fig. 6 is a view similar to Fig. 4, but illustrating in detail the construction of the zero multiplicand keys.

Fig. 7 is a front elevation of the trigger release.

Fig. 8 is a front elevation of thezero multiplier key and carriage shaft release.

Fig. 9 is a fragmentary elevation, Viewed from the left of Fig. 8, and of the catch or trigger of said figure.

Fig. 1,0 is a left end elevation, partly in section, of the device of Fig. 1, showing the link connection between the carriage shaft and an associated shaft.

Figs. 11 and 12 are, respectively, a top plan View and a side elevation of special adding mechanism with which the machine may be equipped.

Figs. 13 and 14 are, respectively, ieft and right hand elevations showing the two faces of the numeral wheels.

Fig. 15 is an enlarged fragmentary top plan View of the numeral wheels and their cooperat ing mechanism shown in the upper part of Fig. 1.

Fig. 16 is a fragmentary side elevation of the audible signal and actuating device therefor, of Figs. 1 and l5.

Figs. 17 and 18 are, respectively, a tcp plan view and side elevation of an extra adding mechanism, With which the machine may be equipped for the purpose, for example, of adding the results of any desired number of multiplications, such as the items of an invoice.

Fig. 19 is a fragmentary top plan view of a numeral wheel and locking mechanism.

Fig. 20 is a front elevation of an electrical calculator or similar device, employing a step motor.

Fig. 21 is a front elevation of a modied electrical calculator or similar device, using a step motor.

Fig, 22 is a front elevation of a step motor with automatic counter or stopping mechanism, for use with calculators and for other purposes.

Fig. 23 is an end elevation of a step motor with automatic counting or stopping device.

Fig. 24 is a fragmentaiy end View, a commutator and brushes, for use with a step motor.

Referring in detail to the accompanying drawings, and particularly to Fig. 1, within the casing I is a wheel shaft 5 rotatably mounted in hori zontally aligned bearings 6 and carrying a plurality of spaced apart numeral wheels 2, which are rotatable with respect to the shaft 5. The shaft 5 is provided at one end with a bevel gear 4, fixed on a horizontal shaft 35 and hereinafter more fully described. Collars l fixed on shaft 5 serve to keep the shaft from moving axially with respect to its bearings and collars 8, located on shaft 5 between each two adjacent numeral wheels, keep said wheels at all times spaced a Xed distance apart.

The final result of any calculation is read on numeral wheels 2, rotatably mounted on shaft 5, each of which carries around its circumference a plurality of identical series of digits, each series running consecutively from il to 9. lIhe number of series is determined by the selected diameter of numeral wheels 2 and the ratio of the driving gears 3 and 4. Where the ratio of gear s to 3 gear 3 is 1:1, the numeral wheels 2 carry nine series of ten numbers each (considering a number), running from 1 to 0, since no multiplication of any two single digits can exceed 9 9 or 8l.

In the present embodiment of the invention, the driving ratio of gear 4 to gear 2 is 2:1, and each of the numeral wheels 2, therefore, carries ve series of numbers each series running from 1 to 0. In this case, for a maximum multiplication, the wheels 2 will rotate nearly through two revolutions. By providing on each wheel a plurality of identical series of numbers, the required speed of their rotation is decreased, so that when the numeral wheels are released, as hereinafter described, the eiTect of their momentum is minimized. The numeral Wheels 2, of course, may be provided with any usual or desired type of cover, provided with aligned openings or windows, and showing only one number of each wheel at a time.

The shaft is provided with a plurality of clutches 9, located between the numeral wheels 2 and axially slidable on shaft 5. Each clutch $3 is provided with aj groove in its bearing for the reception of a pin Il xed in shaft 5, this construction insuring that the clutches 9 will rotate with shaft 5 although they are `axially'slidable thereto. (SeeFigure A coil 'compression spring I3 bears against each 3 left collar Band against each clutch face, urging it'towardthe left, as viewedin Fig. 1, for the purpose of causing a narrow extension finger lll on each clutch to engage the ratchet notches 32 provided in the adjacentface of each numeral wheel 2 (Fig. 2), sothat when shaft 5 is rotated, the numeral wheels 2 will normally be rotated.

A plurality 'of aligned `vertically extending bearing posts i9 are vprovided inthe casing, and each carries pivotally at its topa horizontal lever It, secured to its post by aA bolt i8. To the long arm of each lever is attached one end of a coil spring l5 the other endof which is attached to a fixed pin secured to the framework of the machine.

Each arm M (see also Figs. 4 and 7) is held in the position of Fig. 1 against the action of its coil spring i5 byacatch or trigger arm l5, pivoted at 83 to a Verticalv post Il. Each catch or trigger arm l@ is held in the positionof Fig. 7 by a coil spring 52 whose upperl en d. is attached to the central depending portion of the arm le, and whose lower end is fixed to post ll, the result being that each trigger arm I6 tends normally to occupy a horizontal position. If, however, the right hand end of any trigger arm i5 is struck downwardly, ythe left hand end (as viewed in Fig. 7) will rise and thereby release arm lf3, whose spring l5 will pulll it against the ilange l2 of the corresponding clutch 9, moving it to the right as viewed in Fig. 1, and thereby disengaging nger Il! from its associated ratchet notches and thus releasing that numeralfwhe'el 2fr`om driving engagement with shaft `5.', In this position of parts the released numeral 2v will Ynot rotate if shaft 5v is rotated, but will be held stationary by detent or spring strip 2G (see' Figs. 14 ,and l5) bearing against the ratchet notches,` 2| cut into the face of the annularpart 2a of numeral wheel 2. (See Fig. 14.) The notches 2l' preferably correspond in number and location to the numbered divisions on the wheel periphery 'and alreadyv described.

Detent 26 is supported on frame part or post 2li.,y As shown in Fig. 19, 'fingers Sa, may be attached.`

to arms I4 to engage suitably aligned notches 9b described. That wheel need not be, in two parts 4 in the left faces of numeral wheels 2, when clutches 9 are forced to the right. Over-travel can be prevented in this way.

Each wheel 2 comprises an inner disc portion 2b with central bearing hole for rotation on shaft 5, and an outer annular portion 2a rotatable on the periphery of portion 2b. Concentric face notches 32 are provided in portion 2b and notches 2| are provided in a face of portion 2o. The notches 2|` are preferably egual in number to notches 32. and are equallyspaced circumferentially so that the notches may be brought into radial alignment by means of cooperating detents 20 and 2.3.fastened to post 24 and wheel portion 2b, respectively. Detent 23 and notches 2l serve to align the two portions of the wheel 2, and detent 2B and notches 2i serve to align the outer numbered portion 2a with respect to suitable windows in the cover of the machine. These detents are displaced radially so that they will not collidewhen portion 2b is rotated on shaft 5.

In order to prevent the wheel portions Ealrcm slipping off the associated portions 2b, the latter.,

may be providedwith peripheral or circumferf ential grooves into which pins 25 fastened or. screwed to portions 2a, project so that annular` portions 2a are freely rotatable on central portion 2b, exceptfor theA detents. The pins 25 prevent axial relative movement of the wheel` portions but allow'relative,v rotary movement.

Bearingpost 26 `(Fig`.'4 14) is fastened to wheel portion 2b and carries vshaft 2l'having integral. arm 25 normally inclined tov the planevof wheel:` 2, as indicated in Figure' l5. The other end of. shaft 2l has attached'arm 30e lnormally pro# jecting away from the right face of ,wheel portion 2a at an angle which maybe substantially ninety degrees. Pawl 3l is'pivoted at 31a to arm 300'l adjacent its end and is adapted to engage notches 2l to cause rotation of wheel portion 2a relative to portion 2b when the free end of arm 29k is pushed toward wheel portion 2b. Coiled'spring e' 21a is fastened around shaft A2l and is connected to this shaft and'to bearigpost ,25 so that arm- 29 is normally held in the position shown, a suit-w Pawl 3l, is urgedl against the face of wheel 'portieri` 2aY by means of a'suitable springattached to the pawl and to i arm Sllc. All' wheels` 2f`except the iirst one at the4 able Stop beine provided.

right (Fig. 1) are ofthe composite construction since carry-over does notaiect this wheel. it should, however, have pins 22vonits left face.

The remainder of the "carry-,over mechanism (Figs 1 and15) yincludes parallelrrods 34 and 36a mounted.l in xedposts l3l] an 13llrrespectively. Discs 2c are attached at diarnetricallyl opposite points to sleeves`v 2d which are slidable on rods 34 and 34a.' Compression springs 2el surround the rods, and have their Aleftends held against axial movement Yby pins 3a in the rods.

These springs urge' sleeves 20Ly and accordingly discs 2c, toward the rightso that the sleeves normally abut stop, pinswSbv in. the rods. Each disc 2c hasa cam 3c attached tothe right face thereof and positioned to be struck by the cam pins 22 of anassociatedwheel, 2 as ltsouter rim 2a is revolved in clockwise direction as vseen iny Figure 14. The rst wheel`2 can vof Vcourse be `of composite construction if desired 'but it is not necessary.

Discs 2q have centralvcircular holes 3d large enough to allow rotation of pawls. IIJ,v without inter'ference'andalso to. allow axial displacement of. the discs without'v striking clutches. `9.l Pins or.

arms 22 are of cam shape or bevelled so that they force cams 3c and attached discs 2c to the left (Fig. 15) when they strike and pass cams. By properly proportioning the cams and associated lever arms and other parts any wheel rim 2a will be moved one number or notch forward with re spect to its associated disc 26 whenever the numeral rim 2a of the wheel to the right (Figs. l and 15) has moved through ten numbered spaces; since at that moment a pin 22 of the latter wheel will strike the associated cam 3c and will force the attached disc 2c to the left the proper distance. This causes the adjacent arm 29 to be rotated with its shaft which in turn causes the pawl 3| to move the adjacent wheel element 2a one number higher. The horizontal or axial displacement of disc 2c will move arm 29 through the same angle regardless of the angular position of that arm about shaft 5. It is obvious that carry-over will be effected in the same way regardless of whether the wheel to the left of the actuating wheel is moving or stationary, since the movement of disc 2c is axial and since post 26 and pawl 3| are Carried around by the central portion 2b of the wheel in question.

Although each clutch 9 is urged normally toward the left, Fig. 1, by coil spring I3, the above described clutch release occurs upon movement of trigger arms I6 by reason of the fact that each spring I5 acting on arm |4 is under sufficient tension to overcome the opposing effect of its corresponding coil spring I3.

No clutch need be provided for the wheel on the extreme left, Fig. 1, since the carry-over mechanism performs the necessary action.

This carry-over mechanism (see Fig. 15) includes a pin or arm 22, located preferably on each wheel 2 perpendicular to the left face thereof and in the same axial line as the zero of the wheel. There being five zeros on each Wheel in the present example of the invention, there are, accordingly, five corresponding pins 22 for each wheel.

Referreing t0 Fig. 2 and to the right-hand part of Fig. 1, the horizontal shaft 35, mounted to rotate in end bearings 34 and having xed thereon bevel gear 4 meshing with bevel gear 3, has xed at intervals therealong a series of gears 33, the diameters of which increase in geometrical ratio so that the largest gear has nine times as many teeth as the smallest. Since the ratio of bevel gear 4 to cooperating bevel gear 3 is 221, any angular rotation of shaft 35 will be accompanied by a rotation of shaft 5 through twice that angle.

Still referring to Fig. 2 and to the right-hand part of Fig. 1, with each gear 36 meshes a vertical rack bar 38, whose movement is limited to a fixed vertical path by guide slots cut in fixed plates 31 mounted on posts and in which the rack bars 38 are vertically movable. At the top of each` rack 38 is fixed a numbered push button 39, each push button bearing one of a series of numbers running from 1 to 9, as shown in Fig. 1. These push buttons are the multiplier keys. The zero key will be hereinafter described.

The rack bars 38 are maintained normally in the raised position of Fig. 2 by coil springs 43, one spring encircling each rack bar. The upward movement of each rack bar is limited by a stop lug 4| provided on the bottom of each bar and striking against the bottom of the lower plate 31 at the upper limit of the rack bar movement. A projecting lug 45, fixed to each rack bar, overlies a portion of the curved plate 44 and is in close proximity thereto when its rack bar is in upper position, so that any depression of one of the rack bars 38 will, through its lug 45, cause a depression of curved plate 44, the ends of which are fixed to guide sleeves 43 vertically movable on fixed shafts 42 and maintained in upper position by coil springs 46 surrounding shafts 42 and bearing at their lower ends against the bottom plate of the machine, and at their upper ends against the bottoms of the guide sleeves 43. These springs 43 thus urge curved plate 44 against collars 41 fixed upon the upper ends of stationary guide shafts 42 until one of the keys 39 is depressed. Upon depression of one of these keys, the key lug 45 forces curved plate 44 downward until it strikes a fixed lower limit stop 48. Lugs 45 are sufciently small to pass through the slots 31a, in the lower plate 31. When the key 39 is released, its spring 43 returns it to initial position, and springs 4G, acting on guide sleeves 43, return plate 44 to initial or upper position. Each rack bar 38 has the same length of travel and each bar has the same niunber of rack teeth.

The invention provides mechanism to insure that each multiplier key 39 will be depressed through its full stroke. Referring to Fig. 2, at the right-hand edge of plate 44, a pawl |58 is attached by a hinge pin |69, and a coil compression spring |12 has one end fastened to the plate 44 and its other end fastened to the pawl |68. The spring |12 is fastened on the edge faces of the plate and pawl beyond the end of the hinge pin |39, so that if the pawl is raised, the intermediate portion of the spring moves above the level of the hinge pin and tends to f; hold the pawl in raised position. If the pawl is depressed, the intermediate portion of the spring |12 passes below the level of the hinge pin |69 and maintains the pawl in lowered position. A stop pin |10, fixed to curved plate 44, limits the upward movement of the pawl |58, and its lower movement is limited by contact With the right-hand edge face of curved plate 44. An upper pawl-shifting stop |14 is fixed to the framework of the machine and is struck by the pawl |68 as the pawl nears its upper limit of travel and forces the pawl into lower position so that it will be urged against the teeth of a nXed vertical rack |1| and slide over these teeth as the plate 44 moves downwardly, the teeth of the xed `rack |1| preventing any upward movement of the pawl |68 and plate 44 until the pawl nears its lower limit of travel, where it strikes the lower pawl-shifting pin |13 xed to the base of the machine, which prevents the paWl from moving downwardly any further, so that further downward movement of the plate 44 to the lower limit of its travel will effect the shifting of pawl |68 upwardly about its hinge pin so that the coil spring |12 will hold it in raised position out of contact with the teeth on xed vertical rack |1| so that plate 44 can return freely to its upper position under the influence of coil springs 46. This mechanism insures that any multiplier key 39 must be depressed its full predetermined distance, and thereby effect a predetermined rotation of shaft 35 and predetermined depression of plate 44 and also a predetermined rotation of multiplicand keys 12, hereinafter described, before the plate 44 returns to its upper position. The teeth on rack bars 38 are so located, however, that the rack bars have to be depressed an appreciable distance before their teeth engage the teeth of their respective gears 36. At the left-hand end of curved plate 44 (Fig. 2) is xed a vertical rack 4s, the teeth of which mesh with' the teeth of a .cooperating gear 50 mounted Von shaft which is supported by spaced-apart fixed bearings 53. A fixed guide fork 54 extends upwardly from the base of the machine and embraces the gear 50 for the purpose of preventing axial movement thereof when shaft 5| is moved axially to the right or left, as hereinafter described. The fork 54 also serves as a Vfixed support for shaft 5|, to which the gear 50 is connected to rotate therewith, but to permit vaxial movement of the shaft with respect vto the gear, for which purpose the gear 56 is feathered rto shaft 5| by means of a guide lug in the gear entering an axial keyway 52 in the shaft. By this means, any rotation of gear 150 will be transmitted to shaft 5| regardless of the position of shaft 5| axially with respect to the gear 50.

As shown in Figs. 1 and 8 a plurality of circular beveled grooves 55 are `cut around shaft 5| and are spaced apart a distance equal to the distance between trigger fingers I6, already described. The number of grooves 55 should be the same as the maximum number of digits permissible in the multiplier, not to exceed the capacity of the machine. Preferably the number containing the smaller number of digits is chosen as the multiplier since the distance through which shaft 5| must be shifted, as hereinafter described, and also the number of grooves 55, will then be the minimum. In the present example `of the invention three grooves 55 are shown (Fig. 1). The rack 49 always causes shaft 5| to rotate through less Vthan one-half a complete turn, so that since there is only one keyway groove r52 in said shaft, the keyway never moves far enough to interfere with any of the mechanism cooperating with beveled lgrooves 55.

The shaft 5| is continually urged to move toward the left (Fig. 1) by a spiral tape spring 68 attached to the left-.hand end of shaft 5| and coiling in the fixed tape spring housing 68', and the shaft 5| is released for movement to the left (Fig. 1) .by the following mechanism. Axed bearing 151' extends upwardly lfrom the base of the machine adjacent gear 50 (Figs. 1, 8 and 9) and rotatably supports a trigger shaft 51 fixed axially -with respect to said bearing by a pair of spaced apart collars on said trigger shaft. This trigger shaft has xed thereto at vone vend the horizontally projecting trigger release arm 68, which extends axially under shaft 5| (Figs. 1 and 9) and is normally pressed against the under surface of shaft 5| by a coil spring 66 surrounding the trigger shaft vand having one end xed in the trigger shaft and the other end fixed to bearing 5.1 and tending to rotate the trigger shaft in the `proper direction to cause -the trigger arm 6.8 to bear against the under surface of shaft 5|. To .the other end of trigger shaft 5T a pair of oppositely extending arms 258 and 60 are lattached. The arm 58 has hinged to its outerend a movable extension .59 urged by a spring to occupy 'normally the vposition shown in Fig. 8 and lying below a lug A(il fixed to and projecting from the vertially moving rack 49. The construction is such that downward movement of lug 6| Awill cause the extension -59 to move out of its path, but `when the lug 6| is below extension 59 and moves upwardly into contact with it, `it -will communicate its upward movement to the extension 59 and cause rotation of the trigger shaft V51, lowering trigger arm le'l, thereby dis-1 engaging it from a notch 55 in shaft 5| and per mitting shaft v5| to move to the left under the influence of the tape spring 68.

CII

lThe arm is struck by the zero key, herein-A after to be described. To the side of trigger arm 69 is fastened a stop 56 (Figs. 8 and 9) designed to stop movement of the shaft 5| towards the left after a short displacement upon disengagement of trigger arm 69 from the notch 55. The stop 56 thus prevents shaft 5| from moving to the left through too great a displacement before trigger arm 69 is released by upward movement of lug l(i `to come into contact again with the under side of shaft 5| and thus to engage the next approaching notch 55. When the trigger arm 69 has been so released and again presses upwardly against shaft 5| under the action of spring 66, the stop` 56 rises out of notch 55, into which it has been drawn by downward movement of trigger arm 69', and allows the shaft 5| to move to the left until trigger arm '69 engages in the next approaching p notch 55. In practice, the shaft 5| extends beyond gear 50 a distance equal to the maximum necessary displacement of the shaft 5|. Movement of shaft `5| toward the right is limited by a stop collar lll xed to shaft 5| and abutting against right-hand bearing `53 to limit movement of the shaft 5| towards the right.

`The lug 6| on rack 49 is so located that it causes the release of trigger arm 66 from shaft notch 55 to permit the carriage shaft 5| to shift to the left only after sectors 'l5 on said shaft with their keys have been rotated nearly back to their original or starting position in order to prevent sectors 15 from striking against trigger levers I6 and thereby preventing proper shifting of the carriage.

It has already been stated that it is necessary to move multiplier keys 39 downward a certain distance before racks 38 mesh with gears 36 to rotate shaft 35. It is this distance or movement of the racks 38 without engaging gears 36 that makes possible the rotation of sectors l5 to clear trigger levers i6 when the carriage is shifted. When a multiplier key 38 is depressed and a rack 38 moves downwardly, carrying curved plate 44, the shaft 5| immediately begins its rotation, whereas shaft 35 does not begin to rotate until the instant the multiplicand Zero keys 'l2 are in alignment or striking position relative to triggers I6. If the zero keys are allowed to remain depressed, the numeral wheels 2 will not turn even though shaft 5 be rotated due to the fact that clutches 9 will be disconnected from numeral wheels 2 by the release of levers I4, as hereinbefore described.

Referring now to the Zero multiplier key `64, and particularly to Fig. 8 and Fig. 1, this key is mounted on the stem 63 guided in vertical movement by guide openings in U-shaped plates 65 fixed to a vertical post secured to and extending upwardly from the .base of the machine. The zero multiplier key 64 is urged constantly to its upper position by a coil return spring 7|. Suitable stops are provided to limit the path of movement of the stem `53. Attached to stem 63 (Fig. 1;) is a horizontally projecting lug 52 extending over arm Gil, already referred to, and which is moved downwardly by lug 62 when the Zero multiplier key is depressed. This movement causes downward motion of trigger arm 69 to release the carriage, as already described, so that the carriage shaft 5| is shifted one space to the left (Fig. l) each time the zero multiplier key is depressed.

Referring now to the multiplicand keys, the keys 'l2 (Figs. 1, 3, 4 and 6) are mounted for radial reciprocating movement in flanges 'I6 of sectors 15,

' flange 16.

which are rigidly secured to shaft 5| and are axially spaced apart a distance equal to the distance between trigger arms I6. Referring particularly to Figs. 3 and 4, it will be noted that the rectangular key stems 13 work in slots provided in flanges 16, each key being normally urged to upper position by a coil spring 14, a stop lug 11 on each key limiting upward movement of the key by abutting against the under side of On a face of each sector, guides 19 are provided for an arcuate strip 18, which can move a short distance in either direction about shaft 5| as an axis, the movement taking place with respect to the sector to which the strip 18 is attached.

Referring to Fig. 4, each key stem 13 is pro a vided with a notch 8| formed in the inner edge of the stem, which notch is adapted to be engaged by the slightly projecting bottom edge 85 of the stem guide slot in flange 16, there being a sulficient play in the mounting of the key stem to permit an adequate movement to the right or left, as viewed in Fig. 4, for this purpose. Each stem 13 is urged toward the face of the sector 15 by a flat spring 83` pressing against the edge 1.,;

of the stem 13 opposite the notched edge thereof. Engagement of the forward edge 85 with the notch 8| will therefore occur if the key 12 is depressed, and the key will remain in its depressed position until the lower end of the stem is moved 1:'

to the left to disengage the notch 8| from the edge 85, whereupon spring 14 returns the key to initial position.

Each stem is also provided with a cut-out notch 82 for cooperation with mechanism now to be described. To each circular strip 18 are fastened a plurality of inclined plates 8D (Figs. 3 and 4) which are inclined with respect to tangents to the circular strip, as shown in Fig. 3. The circular strip 18 is provided with a pin to which is attached one end of each of two coil springs 84, the other ends of these springs being fixed to sector 15 so that circular strip 18, if displaced in either direction, will return to its initial position. The inclined plates B0 normally lie below the bottom .1

edges of the key stems 13 so that if any multiplicand key (other than the zero key) be depressed, the lower edge of its stem 13 will strike one of the inclined plates 8U and continued depression of the key will thereby move the circular strip 18 e to the right, as viewed in Fig. 3. As the stem passes downward and notch 8| is engaged by projecting edge 85, notch 82 moves downwardly far enough to permit the cooperating inclined plate 88 to pass through it, thus permitting circular strip 18 to return to initial position under the influence of one of the springs 84. A clearing 88 (Fig. 3) is provided to rock about shaft axis 81 and can be turned to strike the end of arcuate strip 18. When the strip 18 is moved toward the left, as viewed in Fig. 3, by the clearing arm striking against its end, the beveled edge (Fig. Li) of the plate 88', cooperating with the key that has been depressed, will strike the inner edge of notch 82 in stem 13 and will force said stem tov-.fard the left. as viewed in Fig. 4, against the action of flat spring 83, thus releasing the dekey from engagement with projecting edge 85 and permitting it to return to its upper or initial position under the influence of spring 10., circular strip 18 resuming its initial position under the influence of spring 84 as soon as clear ing arm 88 on shaft 81 is moved clear, that is, moved counterclockwise, as viewed in Fig. 3.

All the multiplicand keys except the zero keys are constructed as shown in Fig. 4. Fig. 5 shows details of construction.

The Zero multiplicand keys are constructed as shown in Fig. 6, in lwhich the key button 12, coil spring 1d, notch 8|, forward edge 85, stop 11, and flat spring 83 are all the same as the correspondingly numbered parts in Fig. 4. The righthand lower portion of the zero key stem, however, is extended downwardly beyond the shoul der 88, which corresponds to the bottom of the stem of Fig. 4. Fastened to the bottom part of this downward extension is an inclined plane strip 8s (Figs. 6 and 3), and to the underside of strip i8 is secured the radially inwardly extending beveled lug 98. A horizontally extending wedge Si projects from the adjacent side face of arcuate strip 18. Thus, whenever strip 18 is displaced toward the left, as viewed in Fig. 3, the lug 88 will strike inclined strip 89 and will thus move the zero key downwardly or towards :depressed position until projection 85 engages notch Si. The Zero key remains set after strip 18 is allowed to return to initial or neutral position, and is released only when another key is depressed, thereby forcing strip 18 to the right, so that wedge 8| strikes and releases Zero key 12. Thus, every time the clearing arms 86 strike the ends of circular strips 18, all multiplicand keys except the Zero keys are released, and all the zero keys are depressed and set in position to strike trigger I8 (see Fig. 4), already described. Also, any depressed zero key is released when any other multiplicand key on that sector is de pressed.

Referring to Fig. 4, it will be evident that the multiplicand key stems will move past trigger arm iii except when a multiplicand key is depressed. Upon rotation of shaft 5|, any depressed multiplicand key 13 (Figs. 4 and 7) will strike v against trigger arm I6, thereby releasing the cooperating arm I4 and consequently detaching clutch 9 from its cooperating numeral wheel, as already described. For convenience in construe tion and operation, the angle subtended by keys 12 is preferably slightly more than 90.

Referring to Fig. l, the left end of shaft 5| is provided with a keyway 84 for the reception of the key of a hub 95, which is rotatable with shaft 5I and is held against axial movement with said shaft by a forked bearing column 53 similar to the column 54, but surrounding the shaft in this case. An arm 88 attached to hub 95 has pivoted to its outer end a link 91 (see also Fig. l0). The other end of link 91 is pivoted to the outer end of an arm |88 fixed to hub I8! and keyed to the groove |68 of horizontal shaft |84, which is supported at one end in a bearing |83 and at its other end in a forked bearing |02 similar to the bearing already described. Rotation of hub Ill! will therefore rotate shaft |84, but without itself moving axially. A plurality of peripheral beveled grooves |81 are provided in shaft 84 similar to the grooves 55, already described and provided in shaft 5|. The grooves |81 are spaced apart a `distance equal to the distance between any two adjacent arms |4, which is the same as the distance between trigger arms I6. The number of grooves |31 is the same as the number of grooves 55. A spiral spring H3 in a housing l i3' tends to move the shaft |84 towards the left and corresponds to the spring 68 attached to shaft 5l. The finger |88 of trigger shaft |09 is urged into groove 281 by a spring encircling said shaft having one end fastened thereto and the other end to the lixed bearing support H2.

The other end of the trigger shaf-t has attached thereto a finger 110 hinged, as shown in Fig. 1, and constructed similarly to finger 59, already described, but so that it is operative to release finger 19S from groove 111'1 only when struck vby downward movement of arm 111B and being ineffective when struck by upward movement of said arm. The shaft |1111" is released by finger 1&8 shortly before arm 10G and keys T2 have returned to their initial or starting position, for a reason that Iwill appear hereinafter. A plurality of pins 1115 are mounted on shaft 1134 and correspond in number to thek number of arms 14, except that the arm 14 ony the extreme right of Fig. 1 does not require the pin 125'. These pins serve the purpose of resetting arms 111 after each multiplier key is depressed, and due to the construction described, one less arm is reset each time a multiplier key is depressed. The reason for this is that the carriage, consisting of sectors 15 and keys '12, on shaft 51', is moved7 one space toward the left every time a multiplier key is depressed, and it is necessary to reset only those arms M which register with the sectors '15, and one less armwill register each time a multiplier key is depressed.

The pins 1115 normally extend upward to the right as shown in Fig. 10, and in this position shaft 16d can slide tothe left in its forkedy bearing 1112 andv post bearing 1113l without affecting arms 14% since the pins areslightly below the arms. When shaft 11M is rotated counter-clockwise however, the pins 1115 extend upwardly and will strike against cooperating lever arms 1:1 when finger 1118 is released andthe shaft 12d is moved axially toward the left, as viewed in Fig. 1, by tape spring 113, which is sufliciently strong to overcome the combinedl force exerted on arms 1li by the springs 1-5, already described. Upon striking arms 161 thev pins 105 move said arms counterclockwise about pivots 18 so that the forward tip ends of. arms 114 will strike the beveled forward ends of catches 15 (see Fig. 7) and will raise catches I6 against springs i12, with the result that arms 14 will be caught and held in l initial operating position again. As the shaft 51, and consequently arm 100, nears the end of its return stroke the finger 1118 is released by arm 191! when it strikes against hinged nger 1111, already described, and immediately thereafter the pins 1135 will strike against arms 1dl with the result already stated. As the return stroke of arm 111i? is completed, the pins 125 will be rotated back to their original positions as shown in Fig. clear of arms 1A., and thereupon spring 113 pulls shaft 1114 one space to the left, in which position it is brought to a stop by finger 1138 engaged in the next oncoming groove 111'1.

Referring now to the clearing mechanism, the horizontal shaft |14 is rotatably mounted in end bearings 115 and is held byv suitable collars against axial movement. Fixed tothe left-hand end of shaft 114, as viewed in Fig. lx, is a bevel gear 111, which meshes with a bevel gear 112 keyed on horizontal shaft 1.19, which is located at right angles to shaft |111 and is rotatably mounted in fixed bearings 1211 and is held against axial movement by suitable thrust collars. Extending from shaft 11:1- at spaced intervals are downwardly extending arms 11,5, which ordinarily lie -below the path of pins 22, already described and extending from. the faces of the numeral wheel portionsZa. When shaft 114 is rotated to clear the machine, the arms are moved upwardly to strikeV any of the pins 22 which lie in their several paths, with the result that these pins are aligned so that each numeral wheel Iwill show a zero reading through the cover slot. The-pins 22 on the extreme left numeral whe-el of Fig. l are for clearing purposes only. All the arms |15v on shaft 11A. are long enough to insure that rotation of shaft 1M will cause each arm to strike a pin 22 on each numeral wheel, regardless of the position of any wheel.

Still referring to Fig. 1, a pair of parallel rectangular rods 12.2- are slidably mounted in fixed bearings |28 and are prevented from moving further to the left than shown in Fig. 1 by end abutment pins 1381i. The two rods 122 are connectedV by a cross rod 12,3, which moves in a horizontal path and isv adapted' to strike against the enlarged end flanges 134, 135 and 136 of the shafts 129, 104 and 51, respectively, whenever clearing handle 126, provided on the end of shaft |19, is turned. The top surface of one of the rods 122 is provided with rack teeth which mesh with the teeth of a gear wheel 121 fixed to shaft 119 for the purpose of causing horizontal movement of the cross rod |23 when the clearing handle 12B is turned.

The shaft 129 is slidably mounted in bearings 131 and is constantly urged toward the left, as viewed in Fig. 1, by a coil compression spring 133 located between the left-hand bearing 131 and the end flange 134 of shaft 129. Movement of said shaft towards the left is limited by a right-hand end stop flange 132. A series of pins 131i fixed in shaft 129 extendy vertically therefrom and normally lie in the position of Fig. l, that is, clear of arms I4. Upon operation of the clearing handle |26-, however, cross rod 123, coacting with flange 134, moves shaft 129 toward the right, as viewed in Fig. 1, so that each pin 139 strikes a corresponding arm 14 and moves it far enough to be caught and held by a trigger arm 16 (see also Fig. 7). Shaft 129 is keyed or feathered with respect to one or both of its bearings to prevent it from rotating about its own axis. Upon operation of the clearing handle to move shaft 12,9, as just described, the cross rod 123 will also move shafts 104 and 51 to the right, as viewed in Fig. 1, to return them to their initial or starting positions, where they are held by their respective` holding fingers 1118 and 69, as already described.

Referring now to shaft 8'1 (Fig. 1), this shaft is mounted in end bearings 13'1 iixed to and extending upwardly from the bottom frame plate of the machine. The shaft 8'1 is provided at one end with a bevel gear 125 meshing with a bevel gear 124 keyed on the clearing lever shaft |19, so that whenthe clearing handle 126 is turned, the shaft 81 is rotated, thereby moving arms 86 on shaft 81 to strike the circular strips '18 (see also Fig. 3') and. thereby clear all the multiplicand keys '12 except the zero keys, all of which latter are automatically reset in striking position in the manner already described.

As stated, the bevel gear 1211 is keyed to shaft 119, and is movable axially thereof, being urged normally into mesh with bevel gear 125 by a coil spring |24'. A spring-pressed pawl 1213 is adapted to engage one arm of a bell crank lever, turned by a handle |25', whose other arm is engageable with the bevel gear 124, and acts to hold it against the action of coil spring 12d out of mesh with bevel gear 125 when handle 125' is turned so that the spring pressed pawl retains the bell crank in turned position. Release 13 of the pawl permits the gears to mesh, the bell crank being forced by gear |24 to the position of Fig. 1, under the iniiuence of coil spring |24'. The mechanism here described is used to repeat settings of the multiplicand keys. If the shaft 81 is disconnected, operation of the clearing mechanism will not disturb the multiplicand key setting.

The movement of rectangular rods |22 toward the right is checked when cross rod |23 strikes against bearing posts |28, which serve as a stop for the entire clearing mechanism. The return movement, when clearing handle |26 is released, is effected by spiral spring |21, acting on shaft H9, and which tends normally to rotate the clearing handle shaft I9 in the proper direction to move the rectangular rods |22 as far to the left as possible by means of gear wheel |2I and its cooperating intermeshing rack on one of the rods |22. Movement of the rods |22 toward the left is checked by the stop pins |38a, already described.

It will be seen that by the foregoing construction that one turn of the clearing handle |26 clears the entire machine and also depresses all l zero multiplicand keys.

Referring now to the extreme left-hand wheel 2 shown in Figs. 1 and 16, extending from the face of this wheel it carries the pins 22 and -a plurality of lugs |38, which are located nearer the axis of said wheel than the pins 22 and one of which strikes the pivoted clapper |39 whenever this Wheel makes a rotation of ten unit spaces. The clapper |39 strikes a gong Mil as soon as it is released by the lug |38, being pulled back to its returned, position by a coil spring. In the present instance there are five lugs |38 spaced apart equal distances in the face of the numeral wheel member 2a. The operation of this warning signal informs the operator that further computation performed on the machine will exceed the limits for which the machine has been constructed.

Referring to the method of multiplying, it is merely necessary to depress the desired multiplicand keys 12 and thereupon depress the multiplier keys 39 in inverse order, whereupon the product sought appears at once through the slots in the cover plate overlying numeral wheel elements 2a. A single pull on the clearing lever |26 will clear the entire machine in the manner a1- ready described, so that it is at once ready for another calculation. Suppose, for example, it is required to perform the multiplication 4.'78 57, the number 4 key will be pressed on the third sector 15 from the right, the number '7 key on the second sector from the right, and the number 8 key on the extreme right-hand sector. The number 7 multiplier key 39 will then be depressed and after that the number 5 multiplier key. The answer or product can thereupon immediately be read on numeral wheel elements 2a. It will be observed that no hand shifting of the carriage is necessary. The order of depressing the multiplier keys isinverted, that is, the units digit is depressed rst, thereafter the tens digit, etc., in order to eliminate the additional number of numeral wheels 2 that would be required were the order reversed and the units digit depressed last. 4

The following mechanism enables the machine to be used for adding. Referring to Figs. 1, l1, and 12, the fiat bar |42 is slidably mounted in supports |42', and is constantly urged toward the right, Fig. 11, by a coil spring |43, which move- Ll (i ment is limited by a stop pin |44 on bar |42. The plurality of notches |45 cut in bar |42 allow arms 86 (Fig. 1) to operate freely and also allow sectors 15 and strips 18 to return to their initial positions. When flat bar |42 is moved to the left, however, the unnotched portions of the bar will lie in the path of returning strips 18; consequently these strips will strike against the bar |42 and all multiplicand keys will be re-set at zero when they return to their initial positions.

The iiat bar |52 is moved to the left (Figs. 11 and 12) by depression of a vertically reciprocable adding key whose lower beveled end pushes the beveled end of the bar |412 to the left, and whose shank |46 is encircled by a coil spring |47, which urges the key normally to the position of Fig. 12.

A projection 248 extends horizontally from the key shank and has its outer end overlying a notch in shaft 5|. When the adding key is depressed, the projection |48 enters this notch and thereby prevents shaft 5| from moving to the left when the number "1 multiplier key is depressed for addition. A spring detent |49 enters a depression in the key stem to old it down until it is intentionally pulled up to non-adding position. Loop guides secured to post |42' insures uniform vertical rectilinear motion of the guide key.

To add, theny it is necessary merely to depress the adding key |43, and thereafter, for each number to be added, depress the desired multiplicand keys and. after each such depression, the number "1 multiplier' key. The clearing handle is then pulled and the machine is ready for the next series of numbers to be added. The' depression of the number l multiplier key causes the same number indicated by depressed keys 12 to be set up on the total numeral wheels 2. To clear the machine for the next operation, the clearing handle is operated. After adding, if the next operation is to be one of multiplication, the key iat is pulled up.

Referring now to Figs. 17 and 18, the machine may be equipped with the special adding mechanism illustrated. This mechanism is designed to add the results of any desired number of multiplications, such, for example, as the items of an invoice. That is to say, the individual items are muitiplied, and after the last multiplication is performed, as already described, the total sum can be obtained by the mechanism of Figs. 17 and 18.

For this purpose the wheels 2 (already shown in Fig. l) are provided with thin rim gears |50 attached. firmly to their peripheries and which mesh with similar gears |48 freely rotatable on rshaft |54, which in turn is rotatable in end bearings |52. The numeral wheels 49 adjacent gears |48 are also freely rotatable on shaft and have their peripheries divided into ten equal number areas running from l! to 9 inclusive, as shown. Raehet connections between gears Mil and wheels M9 are provided so that the necessary spaces or areas on wheel-s MS will be carried over even though gears |63 are in mesh with gears |55. Since the wheels |453 rotate oppositely to the direction of rotation of wheels 2, the carryover mechanism will operate in the opposite direction from that already described. This carryover is constructed as previously described. The pins |59 on the annular rim portions of wheels |42 strike cam-s ili'! on plates or discs |55 which are attached to sleeves |58 slidable on parallel rods |55 fastened to arms |'65a and |6517 of forked 15 element |52. Spring |65c normally yieldingly hold sleeves E58iagainst 'stop pins |65d.

Shaft |54, having attached handle |54@ has rotary bearing in arms |85e and carries arms |5| adapted to strike pins |59 and to return Wheels |45? to zero or starting position when handle |5411 is turned. Wheels |49 are constructed with outer numeral rims rotatable on inner discs, with face notches in the rim, as previously described for Wheels 2. The carry-over mechanism as ndicated in Figure 17 is of similar construction as before. Wheels 2, as lshown in the latter figure, would, however, be rotated in a direction opposite to that previously described, or the numerals on Wheels |49 should be in reverse order.

l-ook |58 (Fig. i8) is attached to element |52 and will be engaged by latch |62a pivoted to post |63, when forked element |52 is suiiiciently rotated counterclockwise about pivot |64 on foot |53. Tension spring |8| normally holds latch |6211 in position to catch and hold hook |68. Abutment cam |55a, attached to extended clearing shaft |l9, may be rotated to force forked element |52 counterclockwise so that gears |48 will be brought out of mesh With gears |58 While Wheels 2 are being returned to Zero position by the clearing mechanism'. In this way, the totalizer Wheels 49 preserve their readings until cleared. When wheels 49 are not in use, element |52 is pushed back so that latch |62@ holds hook |68 and so keeps gears |48 and |58 out of engagement. When it is desired to use the totalizer Wheels 48, lever |92 is depressed so that latch |62a releases catch l 88 and spring |56 then pulls element |52 over so that gears |48 engage gears |58 on Wheels 2. Cam |5511., when rotated, moves element |52 enough to disengage gears |48 and |58 but not sumciently to cause latch |62a to hold hook |69.

The general theory of operation of the present machine is as follows. Instead of operating a multiplier handle or key the same number of times as the number of the multiplier digit, as has been the custom with some machines, gear ratios are employed so that depression of the 9 multiplier key, for example, will rotate the total numeral Wheels 2 through nine times as many unit divisions as Would be the case When the' number l multiplier key is depressed. Similarly, depression of the number 5 multiplier key one time r causes the total numeral wheels 2 to rotate through ve times as many spaces as when the number l key is depressed, and a corresponding effect is produced by depression of any of the other numeral keys. When the zero multiplier key is depressed, the carriage is simply shifted one space to the left.

By means of the curved plate 44, rack 49 and gear 58, the shaft 5| and keys 12 are rotated through exactly the same angle every time a multiplier key of any numerical Value is depressed its full distance. The zero keys 12 are so located that lever arms I4, and consequently clutches 8, are released at the instant any multiplier rack 38 touches its cooperating gear 36, with the result 'that the' number 9 keys 12 will be in such position that clutches 9 are released at the instant that numeral Wheels 2 show the reading 9 after the number l multiplier key has been depressed. Evidently, then, if the number "3 multiplier keyl for example, is depressed, the numeral Wheels 2 will rotate through 3X9 or 27 unit spaces, since the gear ration between the number 3 rack and its cooperating gear 36 is three times the ratio for the number l key, Whereas the ratio between rack 49 and gear 58 tents |83.

always remains the same;` In other' Words, the reading of any numeral wheel 2` is proportionate to the reading of the multiplier key which is depressed, assuming that the same multiplicand key is kept depressed. 1f instead of allowing the number r9" multiplicand key to strike' trigger arm i5, the number "3 multiplicand key is depressed, then this particular numeral Wheel 2 will rotate throughy only one-third as many spaces as it did in the previous example before its clutch 9 will be released. The reading will then be 3 3 or 9, which is one-third of the previous product 27. Thus it will be evident that the reading of any numeral Wheel 2' When it lias been disconnected from its clutch and remains stationary, except for the carry-over, is proportional to the numerical value of the depressed niultiplicand key in register with it and is also proportional to the numerical value of the` multiplier key which is depressed. The reading on numeral wheel 2 is therefore proportional to the product of lthe numerical value' of thetwo depressed keys. The product of each digit of the multiplicand by each digit of the multiplier is therefore registered on the proper Wheels 2 and these products are automatically added by means of the clutch devices, the carry-over system and the automatically shifted carriage.

In Figure 20 motor |66 is of the type described in my cti-pending applications, Serial No'. 598,502, led June 9, 1945', and Serial No. 671,204, filed May 21, 1946. This ymotor can be operated in steps of predetermined angulardisplacement. It is supplied, preferably, With direct current from lines |61 and |68v which current is distributed to the three phased sections of the motor by means of commutator or distributor |69 the details of which are described inthe above applications. l l

Brush holder |1|J` is fastened to motor |66 and carries brush |1| which is electrically connected with one of the field sections by means of conductor |12 which leads to conductor |13 connected to a field section. 4Line |61 is connected with metal bar |14 bolted to post |15 which is bolted to base plate |16. Mico or other insulation |11 is placed between bar |14 and post |15 and the bolts are insulated s'o that bar |14 is not electrically connected with post |15.

Keys |18, |19, |80, and |8| are vertically slidable in slots in bar |14 and plate |82' which may be lifted by the clearing mechanism (not shown) to return any or all keys to the normal positions shown Where they are supported by cle- These detents also act to hold the keys in depressed positions, by pressing into suitable notches in the keys. The key buttons are of insulating material and the keys may be insulated in any Way desired.

Contact pin |84 is carried on arm |85 fastened to the motor shaft |86 which also carries slip' ring |81q. against which brush |1| is pressed by a spring. Arm has paw] |86 adapted to strike toothed wheel |81 Which is pivoted to post |88 extending from bar |14 so that Wheel |81v can be rotated in a horizontal plane. Similar wheels |88 and |89 are similarly mounted and are adapted to be struck by pawls or arms |98 and |9|, respectively, extending from the faces of discs |92v and |93 which are fastened to hubs having rotary bearing onV shaft |94 extending from post |15. Similar disc |95I is rotatable ori shaft |94 and may -be rotated in steps by gear or toothed Wheel |89 which is meshed` with circular teeth cut in the left face of disc |95. By means of siinilar teeth cut in the left faces of discs 92 and 193, these discs may be rotated in equal steps by means of meshed, toothed wheels or gears 181 and |88, respectively. Discs |92, |93, and 195 carry respective contact pins |96, |91 and |98 aligned to strike the respective associated keys 119, 189, and |8|, when the keys are depressed. Contact pin |84 likewise may strike key |18 when that key is depressed. The keys may be of highly conductive material or may have attached contacts to be struck by the contacts on the electrically conductive discs. Any suitable clearing mechanism, similar to that previously shown or of other design, may be used to set the motor and discs to zero or starting position. This clearing mechanism may comprise rotatable arcuate gears |99 mounted on shaft 290 which is rotatable in suitable bearings to engage aligned gears on the motor shaft and the hubs of discs 192, |93 and |85. There are ratchet connections between the gears and the shaft and hubs or between the hubs and discs. Suitable stops are provided or ciearing arms can strike arms |85, |98, |91, and iia, for aligning purposes.

In operation, if it is desired that motor |69 revolve through a predetermined number of revolutions or steps and then stop, the one key 118 will be depressed for one revolution, for instance. Then, motor |66 will be energized, as described in the previous applications, to rotate through one revolution in steps. When contact |84 is rotated through a full revolution, or through a definite number of steps, depending upon the starting position of contact 184, this contact will strike depressed key |18 to close the circuit including line |91,bar |14, key |18, contact |84, arm |85, slip ring |81, brush 11|, conductor |12, one field section, and line |88. When this one field section is energized the rotor of the motor is locked in position.

If a greater number of revolutions of the motor is desired, then key 119 will be depressed and gear or toothed wheel 181 will .be moved through one angular tooth width for each revolution of the motor and pawl |86. After a predetermined number of revolutions of the motor, depending upon the number of teeth in wheel |81 and the number of associated teeth in the face gear of disc |92, contact 196 will be rotated to strike key 119 and so to close the circuit to the eld section connected with conductor |12. This causes the rotor to stop revolving immediately due to the peculiar construction of the motor which also acts as a magnetic brake. Electrical connection with any disc and slip ring |81a is maintained by a flexible brush connecting the motor shaft with shaft |94, or other connections may be used. Slip ring |81a is electrically connected with the shaft of the motor.

Similarly, progressively higher numbers of revolutions of the motor before stoppage can be obtained by pressing keys |89 or |8|. The ratios of revolutions may be in tens or in other proportions, Any suitable ratios and any desired numbers of keys can be used, to cause the motor to revolve through any desired number of steps, or revolutions, before automatic cut-o occurs. This motor and system are therefore highly useful in calculating or computing machines, bookkeeping machines, and similar devices, since a predetermined number of movements of the rotor, in small angular steps or in revolutions as desired, may be automatically obtained merely by pressing one or more keys. The drawings are largely schematic and serve to illustrate general principles rather than details of construction which can be widely varied. The keys can conduct grid currents of tubes. Clearing bar |82 can be raised by any suitable mechanism to reset the keys to the positions shown. Toggle switch 29|, fastened to post |15, is arranged so that it can be manually closed and so that it will be struck by arm 292 of shaft 299 and will therefore be opened when clearing shaft 299 is rotated through an angle. If switch 29| is connected in series with line |68, the motor will be started when switch 291 is closed and the current will be cut off when the clearing mechanism is operated.

The discs may have equally spaced numerals on their peripheries for adding or counting purposes. One or a plurality of sets of numerals may be used.

In Figure 21, motor 293 is similar to motor |98 but distributor |69 is omitted. Keys 294 are vertically slidable in slots in bar 295 which is suitably fastened to the framework 299 of the device, shown broken away. Compression springs 291 are placed around the key stems between the buttons and bar 295 and normally keep the keys in the positions shown. The keys are limited in upward movement by attached pins 298 striking the under side of bar 295. The keys vary progressively in length according to geometrical or any other desired ratio.

Bar 299, having integral legs 219 and 21| at right angles, is placed beneath the keys and in alignment therewith. Leg 21|' is vertically slidable in a slot 2|2 in post 213 attached to base 214, and leg 2|9 is vertically slidable in an edge slot or groove 215 in post 2|6 attached to the base. Compression spring 2|1 is fastened to the upper end of post 2|6 and to bar 299 and normally supports this bar in the position shown against a suitable stop or against the lower ends of keys 299, as desired. A similar spring can be used for the other end of the bar.

Leg 2|9 is of metal and has a slotted edge forming teeth 218 the spaces between which are preferably filled with insulating material such as Bakelite. Three brushes 219 are mounted in insulating block 229 fastened to the motor. Conductors 221 electrically connect the brushes with the three motor section windings. Line 222 is flexibly connected with leg 2|9 and the other line 228 is connected with the junction of the three motor windings. Teeth 2|8 normally extend downward to a position slightly above the uppermost brush 2 |'9 so that no contact with the brush is made. The strip 224 is of insulating material.

Disc 225, with concentric depressions or dimples 225 in a face thereof, is fixed to the motor shaft. There should preferably be one depression for each rotor step. Detent 221 is fastened to the motor and is aligned so that it will fall into any one of the depressions when the rotor teeth of the motor are at predetermined position relative to the stator teeth, which position may be with the rotor teeth near their maximum forward swing for any one step. Shaft 228 has rotary bearing in post 229 fastened to base 2id and is aligned with the shaft of the motor. Shaft carries disc 239 coaXially therewith and this disc carries ratchet 23| which is adapted to en fige concentrically arranged notches in the left f of disc 225. These notches preferably coin in angular and radial position with depressi. 22S.

If desired, the keys 294a may be horizontally slidable in slots in leg 21| and the right edge of post 2|3 may have a vertical slot of sufficient chosen; position.

`windings .will be energized inv sequence.

width .tol allow.- passage yof' thekeys whilerin the positions shown. If; however, a .key is pressed so `that'it projects tothe left of leg 2 i l, then that keyi'willstrike the lefttop-edgeof post 2&3 to stop.. downward movement. ofi bar 229. at the In .orderto .reset the Vkeys to starting `orzero position, camrbarr232 is moved tothe right through bearing post 233 so that anyfkey or keys projecting will be pushed back tozero position when spring 2lr'eturns barde@ andsintegral legs tothe uppermost position.

In operation, whenitlis desired: to rotate the shaft of the motor. through the minimum numberr of .steps,l the. shortest key 2MV will be depressed vits full travel'softhat bar29 and consequently .teeth 2l8will be moved downward. As

each tooth passes the three brushes the rotor -willfbe moved through three steps sincevthe three If it is desired that the rotor move through .only one steprthe shortest key will be ofV such length that the bottom tooth 2li;J moves downward only enough tol touch the first brush 2 i9. If two steps ofdmovement of the rotor are desired then the bottomtooth 2|8fshould touch onlythe iirst two lbrushes 2li). The teethv should be separated suificientlysothat only one toothl touches a brush at anyone instant, unless reverse braking is desired, as described in one 'of the above applications.

If the maximum i step idisplacement ofthe rotor is desired, the longestkey will befdepressed and the intermediate keys will be depressed for intermediate displacements. rIhe number of steps displacements yfor the keys canbe in the ratios of tens, hundreds, etc., as in usual calculatingrmachines of other type or vother ratio-s can be chosen. As the rotor ismoved in steps, detent 22T! being resiliently urged'into a depression 226 will insure proper-alignment to produce a denite numeral alignmentwith a window, for azcal-culating machine.

By meansv of ratchet-23l shaft 222 -is rotated in forward directioninfsimilar steps and detent 2311,.` attached to post 229,- may be usedinv connection with depressionsin'a iaceof disc 232 to align that disc properly' in steps. The ratchet allows shaft 228 to remain in'position when the rotor of motor 203 is moved in steps in reverse directionas teeth' 2 l`8vsweep upward past brushes 2 I9, after lrelease of a'key, due to action of spring 2i '1. If it is desiredthat the-rotor do not reverse as teeth- 2li! 'are lifted to'starting position, these teeth or brushes y2li! can be automatically displaced by means of a rocker and cam, or otherwise, so that no4 contact is made'during return.

Shaft 228 can be substituted for shaft 5 or a similar shaft to drive a plurality of numeral wheels. In numerous lapplications including calculating machines, bookkeeping machines, tabulators of various kinds, analyzers, totalizers, and sequence devices, it is desirable or essential that a shaft or shafts bevrotated through a determinate number of steps or revolutions. The motors and controls shown in'l'igures 20 and 2l are very advantageous for the purposes mentioned, and for other uses, since the shaft'can be'rotated through predetermined angles and can be stopped at desired positions. By this means, also, the motor can be operated at relatively low speeds so that clutches and other mechanism can often be eliminated.

In Figure 22, motor |66 and distributor' |69 can be of thesame construiction 4as described'in 20 connection withrthe `gdevcei showny in Figure .120, andy can be connectediwith linesxl''l and Iin the same manner; The three .section windings for inagnetizing the rotor or statorteeth, or both, are indicated` at A, B, and C. The .motor shaft teta isthreaded andrihas surrounding threaded collar 235 vwhich is slottedrtoslide along bar`236 attached 'to the motor. This barhas scalei23'l relative towhich index 238 on collar 235 can be set by .liftingspring-pressed.pin4 239 in a `hole in the collar so the latter can be` slipped along shaft ia. Pinv Ei'normally engages the threads or shaft'la so that collar 23d-Will be moved toward'norrnallyfopen resilient contacts 249 mounted onl insulatingrarm- 24| attached to themotor. Onevcontact 22d-is connected with `line it? -and the other with the inlet terminal of winding-A.

In operation, index 23a-fis' set relative to the scale on -bar 23S-to indicate the number of revolutions -or steps through which it is desired that the rotor move before stopping. The motor-is then started by energizing-lines |51 and H53 and the motor moves in steps until vthreaded shaft 586e moves block or slide 235`tothe left so that it forces the'contacts'ZLl together. Winding A then becomes continuously energized so that the rotor is magnetically locked against further movement. When it isdeSiredftO-'reset block 235, pin 423e-is pulled up and the'block-V is moved to the'position desired. Thismotor can be used for purposes described;

A'modiiication of the motor `control of Figure 22 is-shown in Figure A23.' Metal disc 242 has attached bearing2sleevef2l3 which is rotatable on annulus 2M of'insulatingxmaterial, attachedto motor 162. Like numerals indicate like parts as in `Figure 22.' Slip ring125-is-fastened around insulating sleeve 226 which isfastened around motor shaft |8519. Resilient brush 24"! engages slip ringr2li5 and is supported Aonan insulating blockv fastened to the machine. Similar brush 228 isconnected with line E61. Handle 229 is attached tothe'rear face of disc 222. Contact 25H3 is attached to'disc26l2 and'ispositioned to be struck bycontact arm 25! attached'to the rear edge of'ring-21l5.`

Irl-operation, disc 2ii2fis'rotatedby handle 2139 until a'numeral on the circularscale on the disc isI in register with indexf238aon the motor. Then the 'motor shaft lwill be rotated in` steps; incounterclockwise direction,` say, lafter being'energized When contact 'army 2M strikes contact25il, the circuit fronrline i 'ithroughone of the windings is-completed, asbefore,- tolock the rotor. Disc 2132 'and attached lcontact'Zil' Amaybe Vrotated to any desired position to determine .thenumber 'of steps through which'th'e rotorwillibe revolved before stopping.

Figure 24 shows one iorrnof distributorwhich may comprise the unit-1:29." Line I lisfconnected with resilient brush'252x'pressing'against slipring 253^integral withmetal disc 3254"'which'has:v peripheral inserts 2 5:5 of' insulatinginaterial. such as Bakel-ite. Therefore;H as metal te'eth"25 are ro-l tated'beneath brushes 251,252', and 25S, mounted in rinsulating* block 2 62, the current will be .distributed'to the 'conductors'Z 13in proper orderto causerotation'oftthe motoras described in .the above mentioned applications.'A The. teeth.l 256 can -be separatedso that onlyonetooth willlbe incontact with a brush at anyone time, or'they can-bc more V4closely spaced, l as .showmso that braking ieiect 'in certain windings willfoccur. at proper times, inorderito iprevent oscillations ofl the rotor'.`

While I have shown and described modifications of my computing or calculating machine and associated devices, it is obvious that numerous changes of detail and variations can be made without departing from the broad principles of the invention.

What I claim is:

1. A calculating machine including computing mechanism comprising a plurality of numeral Wheels, a numeral Wheel shaft on which said wheels are mounted, a gear carrying shaft geared to said numeral Wheel shaft, said gear carrying shaft having thereon a series of gears the diameters of which increase in one direction in geometrical ratio, and a depressible multiplier key controlling each gear of said series.

2. A calculating machine including computing mechanism comprising a plurality of numeral Wheels, a numeral Wheel shaft on which said wheels are mounted, a gear carrying shaft geared to said numeral wheel shaft, said gear carrying shaft having xed thereon a series of gears the diameters of which increase in one direction in geometrical ratio, and a depressible multiplier key with a rack bar attached thereto for meshing with and controlling each gear of said series.

3. A calculating machine including a plurality of numeral Wheels, a plurality of multiplier keys, a rack bar associated therewith, a multipli-cand key shaft carrying a gear in mesh with said rack bar, a plurality of groups of multiplicand keys associated with said multiplicand key shaft, said shaft being rotated through said gear and rack bar through the same predetermined angle on each depression of any multiplier key.

d. A calculating machine including a plurality of numeral Wheels, a plurality of reciprocating multiplier keys controlling said Wheels, a plurality of multiplicand keys, a multipli-cand key shaft carrying said keys and rotatably and axially movable, devices controlled by said multiplier keys for causing rotation of said multiplicand key shaft on depression of said multiplier keys, a releasing element actuated on the return stroke of any multiplier key at the moment it nears the end of such stroke to release said multiplicand key shaft for axial movement, and spring means for moving said shaft axially When so released.

5. A calculating machine including a plurality of numeral Wheels, a plurality of reciprocating multiplier keys controlling said Wheels, a plurality of multiplicand keys, a multiplicand key shaft carrying said keys and rotatably and axially movable, devices including a rack controlled by said multiplier keys and a gear meshed therewith and slidable on said multiplicand key shaft for causing rotation of said shaft on depression of said multiplier keys, said shaft having a plurality of peripheral grooves therein, and a releasing element cooperating successively with said grooves and released on the return stroke of any multiplier key at the moment it nears the end of such stroke to release said multiplicand key shaft for axial movement, and spring means for moving said shaft axially when so released, thereby bringing the next groove in said shaft into holding engagement with said releasing devi-ce.

6. A calculating machine including a plurality of numeral wheels, clutches cooperating therewith, a lever arm controlling each clutch, a releasable trigger for holding each lever arm in predetermined position, a series of rotary sectors each carrying a plurality of depressible multiplicand keys, one of said triggers being released 22 by a depressed multiplicand key when its sector is rotated, and spring means acting on each lever arm and operable on release of its trigger to move the corresponding clutch out of engagement with its numeral wheel.

7. A calculating machine including a pluraliti7 of numeral wheels and a plurality of sectors each carrying depressible multiplicand keys including zero keys, triggers actuated by said multiplicand keys for controlling said numeral wheels, said triggers being actuated by said keys, a clearing mechanism shaft and devices operated thereby for releasing all depressed multiplicand keys, except said zero keys, to clear said triggers but depressing all undepressed zero keys into position to actuate said triggers.

8. A calculating machine including a plurality of numeral wheels and :a plurality of sectors each carrying depressible multiplicand keys including Zero keys, triggers 'actuated by said multiplicand keys for controlling said numeral Wheels, said triggers being actuated by said keys, a clearing mechanism shaft, devices operated thereby for releasing all depressed multiplicand keys, except said zero keys, to clear said triggers but de- -pressing all undepressed zero keys into position to actuate said triggers, and devices on each sector for releasing any depressed zero key on that sector when any other multiplicand key on that sector is depressed.

9. A calculating machine including a plurality of numeral Wheels, a plurality of reciprocating depressible multiplier keys controlling said wheels, a plurality of multiplicand keys also controlling said wheels, a multiplicand key shaft carrying said multiplicand keys and rotatably and axially movable, devices controlled by said multiplier keys for causing rotation of said multiplicand key shaft on depression -of said multiplier keys, a releasing element actuated on the return stroke of any multiplier key to release said multiplicand key shaft for axial movement, spring means for moving said shaft axially when so released, and clearing mechanism including a sliding member for returning said shaft in an axial direction to its initial position.

10. A calculating machine including a plurality of num-eral wheels, clutches cooperating therewith, =a lever arm controlling each clutch, a releasable trigger for holding each lever arm in predetermined position, a series of rotary sectors each carrying a plurality of depressible multiplicand keys, one of said triggers being released by a depressed multiplicand key when its sector is rotated, spring means acting on each lever ar-m and operable on release of its trigger to move the corresponding clutch -out of engagement with its numeral wheel, a spring controlled reciprocator for returning released lever arms to their initial positions, and clearing mechanism including a slide for moving said reciprocator in lever-armreturning direction.

11. A calculating machine including a, plurality of numeral wheels, -clutches cooperating therewith, a lever arm controlling each clutch, a releasable trigger f-or holding each lev-er arm in predetermined position, a lever arm resetting shaft mounted for rotatable and axial movement, a plurality of resetting pins carried thereby, a mul- #tiplicand key shaft, a series of rotary sectors thereon each carrying a plurality of multiplicand keys, a plurality of depressible multiplier keys, -a link connection between said shafts to cause them to rotate together, devices connecting said multiplier keys with said multiplicand key shaft for 

